The present invention relates to a lagoon partitioned for hog waste treatment, and the method of waste treatment in said lagoon.
Hog waste has been processed by a lagoon method in the US and in some European countries. According to a recent report, there are about 4,500 active hog waste lagoons and 1,700 inactive lagoons just in the state of North Carolina alone.
A lagoon is a simple basin structure, either naturally formed, or artificially built with outer perimeter walls. It is designed to hold animal waste from livestock operations. The lagoon method basically involves dumping of waste such as manure and urine from livestock operations, and waiting for its natural stabilization. After simple retention, the supernatant of the aged waste is reused as pen washing water or sprayed onto the fields. Currently, in many cases, lagoons are rapidly becoming over-capacity, and the only way to relieve them seems to involve applying the wastewater therefrom to the adjacent fields. However, this method poses environmental and public health problems, including extremely unbearable odor, contamination of land by highly concentrated nutrients, and diseases caused by various pathogens.
There have been many efforts to reduce the environmental side-effects associated with the animal waste lagoons. U.S. Pat. No. 5,736,049 focuses on odor control by using aeration devices on top of a lagoon but does not provide further information on other environmental and health problems.
U.S. Pat. No. 6,190,566 discloses a method of replacing an existing lagoon with a wastewater treatment plant for odor control and reduction of waste volume by burning solid waste and sludge in conjunction with biological treatment of wastewater. The method seems to provide an alternative in reducing environmental side-effects caused by animal wastewater. However, the method does not seem to be an economically viable option from the perspective of livestock operators since it involves constructing a separate wastewater treatment plant requiring a substantial engineering work with high operational costs.
Another possible approach to solve these problems of existing lagoons is disclosed in U.S. Pat. No. 5,863,434, which describes an application of a sequencing batch reactor (SBR) as an alternative wastewater treatment method. However, this approach lacks cost-effectiveness from the perspective of livestock operators and is questionable as to how it can be applied to a full-scale lagoon.
The solutions thus supplied so far involve stopgap measures, focusing only on one particular set of problems, such as foul odor of lagoons, or a wholesale application of the conventional technology of wastewater treatment facilities to the livestock operations without consideration for cost effectiveness. Indeed, the removal of odor and nutrients from the existing lagoons can be achieved by such installation of complicated treatment facilities, but this would require a tremendous amount of investment, which in turn would hurt the bottom-line competitiveness of livestock operators.
Therefore, for environmentally sustainable livestock operations, an introduction of a new treatment system seems to be inevitable. Nevertheless, such a system should be economically viable since among other reasons a livestock operation is a highly competitive business. Against this background, the present invention provides a method of retrofitting of an existing lagoon in light of a new treatment system of a partitioned lagoon at a minimum cost, and the method of treating hog waste with removal of excess nutrients and odor.
The objective of the present invention lies in providing an environmentally sustainable partitioned lagoon, and the method of treating hog waste at a minimum cost. The present invention can be applied to newly built lagoons, or to currently existing lagoons with minimum construction work.
More particularly, the present invention relates to a lagoon for hog waste, which is partitioned into zones separated by walls, comprising a first zone for storing and settling hog waste, a second zone for carrying out sequence batch reaction onto the supernatant from the first zone, a third zone for storing the processed liquid materials from the second zone, and a fourth zone for fermenting the solid materials from the first and second zones, wherein a passageway with a pump is installed between the respective two zones for transference of solid and liquid waste materials.
In order to achieve said objectives, the lagoon for hog waste according to the present invention further comprises a blower to feed air into said second zone for aeration, in which the air is collected from the odorous zones such as said first and fourth zones. Odor causing matters are removed by biological degradation and adsorption in said second zone. The present invention further comprises covers installed over said first and fourth zone for odor control.
Another objective of the present invention is to provide a lagoon for hog waste, which is partitioned into zones separated by walls, comprising a first zone for storing hog waste, a second zone for storing the same after passing through a solid and liquid separator installed there between, a third zone for carrying out sequence batch reaction onto the supernatant from the first zone, a fourth zone for storing the processed liquid materials from the third zone, and a fifth zone for composting the solid materials from said solid and liquid separator and from the third zone, wherein a passageway with a pump is installed between the respective two zones for transference of solid and liquid waste materials.
The lagoon for hog waste according to the present invention further comprises a blower installed between said second and third zones for blowing gas from the second zone to the third zone. The present invention further comprises covers installed over the first and second zones, and over the fifth zone for odor control.
Another objective of the present invention is to provide a method of treating hog waste in a lagoon, which is partitioned into zones separated by walls, comprising transferring hog waste to a first zone for storing and settling the same; carrying out sequence batch reaction in a second zone onto the supernatant transferred from the first zone; storing the processed liquid materials therefrom in a third zone; and fermenting in a fourth zone the solid materials from the first and second zones.
To facilitate the treatment process, the method of treating hog waste in a lagoon according to the present invention entails placing packs of zeolite ceramic balls into said second zone for sequence batch reaction. Further, it may also entail installation of a baffle to the first zone. Moreover, during the sequence batch reaction, a carbon source of methanol or glucose may be added to the second zone for the treatment process therein. For odor control, the method involves blowing by a blower the gas collected from the first and fourth zones to the second zone for sequence batch reaction, and installing covers over said first, and fourth zones.
Another objective of the present invention is to provide a method of treating hog waste in a lagoon, which is partitioned into zones separated by walls, comprising transferring hog waste to a first zone for storing said hog waste, a second zone for further storing the same after passing through a solid and liquid separator installed there between, carrying out sequence batch reaction in a third zone onto the supernatant from said second zone, storing the processed liquid materials therefrom in a fourth zone, and composting the solid materials from said solid and liquid separator and from said third zone.
Here, as described above, the method may involve placing packs of zeolite ceramic balls into said third zone for sequence batch reaction; installing baffles to the first and second zones; adding a carbon source of methanol or glucose to said third zone for sequence batch reaction; blowing by a blower the gas collected from the first and second zones and the fifth zone to the zone for sequence batch reaction for odor control; and installing covers over said first and second zones, and over said fifth zone for odor control.
Another objective of the present invention is to provide a method of treating hog waste by a lagoon, which is partitioned into zones separated by walls, the end products of which are reusable as odorless solid and liquid fertilizers of high quality at a minimum cost.